A thermal desorption injection device for a breath molecular analysis gas chromatograph

Abstract

This invention discloses a thermal desorption injection structure device for a gas chromatograph used for breath molecular analysis. The injection structure device includes: a substrate with several channels on its end face, with channel walls formed between adjacent channels, and material filled in the channels; and a cover plate covering the substrate, the distance between the cover plate and the top of the channel walls being less than the diameter of the material. The channel walls, channels, and substrate are fabricated using a step-by-step etching method, and the feed inlet, air inlet, and air outlet are also etched using step-by-step etching. The thermal desorption injection structure device for a gas chromatograph used for breath molecular analysis provided by this application fills the channels on the substrate with material, which can effectively increase the contact area between the material and the substrate, achieving rapid and uniform heating of the material particles and effectively improving the thermal desorption efficiency. The substrate is designed with partitions, and each partition is equipped with a heating resistor and a heat insulation plate, enabling precise partition heating and temperature control.

Description

Technical Field

[0001] This invention relates to the field of thermal desorption device technology, and in particular to a thermal desorption sample introduction structure device for a gas chromatograph for exhaled molecular analysis. Background Technology

[0002] Thermal desorption injection is a process that extracts and concentrates volatiles from a complex matrix and rapidly introduces them into GC or GC / MS analysis. Thermal desorption instruments are essential pretreatment equipment in VOC analysis laboratories.

[0003] Current thermal desorption injection devices are bulky and cannot effectively distinguish between regions when loading different materials; they cannot perform zone heating and precise temperature control of zones; they cannot perform zoned thermal desorption; the thermal contact surface of the material is insufficient; resulting in the need for long heating times to achieve higher thermal desorption efficiency; and they cannot set specific thermal desorption temperatures for two VOCs with similar separation. Summary of the Invention

[0004] This application provides a thermal desorption injection structure device for a breath molecular analysis gas chromatograph, which solves the technical problems of insufficient thermal contact surface of materials, uneven heating, inaccurate temperature control, and low thermal desorption efficiency in the prior art.

[0005] This application provides a thermal desorption injection structure device for a gas chromatograph used for exhaled breath molecular analysis, comprising:

[0006] A substrate having a plurality of sequentially connected and recessed filling regions, each filling region having a plurality of channels, with channel walls formed between adjacent channels, material being filled in the channels, and partitions being provided between the filling regions, the distance between the top of the cover plate and the partition plate being less than the diameter of the material.

[0007] A cover plate that covers the substrate, wherein the distance between the cover plate and the top of the channel wall is less than the diameter of the material.

[0008] In some embodiments, the distance between the channel wall and the edge of the filling area is greater than the diameter of the material.

[0009] In some embodiments, a feed port is provided on the substrate for each of the filling regions, and the feed port is connected to the side of the filling region.

[0010] In some embodiments, the filling regions at corresponding ends on the substrate are respectively provided with an air inlet and an air outlet, and the air inlet and air outlet are connected to the corresponding filling regions.

[0011] In some embodiments, the air inlet, air outlet, feed inlet, channel wall, and filling area are etched in stages, and the etching depths of the air inlet, air outlet, feed inlet, channel wall, and filling area are different.

[0012] In some embodiments, a wide-angle opening is provided at the connection between the air inlet and the air outlet and the filling area.

[0013] In some embodiments, the thermal desorption sample introduction structure device further includes a controller. A heating module and a first temperature sensor are provided on the back side of the substrate for each of the filling areas. The heating module and the first temperature sensor are both connected to the controller. An insulating layer is deposited between the heating module and the temperature sensor and the silicon substrate. The insulating layer is SiO2 or SiNx.

[0014] In some embodiments, heat insulation layers are provided on both sides of the partition.

[0015] In some embodiments, the thin films on the surfaces of the heating module and the first temperature sensor are fabricated using magnetron sputtering or vapor deposition equipment. The thin film on the surface of the heating module is made of one of Au, Pt, Al, and Cu; the thin film on the surface of the first temperature sensor is made of one of Pt and Ni.

[0016] In some embodiments, the substrate is a silicon wafer and the cover plate is quartz glass.

[0017] The beneficial effects of this application are as follows:

[0018] The thermal desorption injection structure device for the exhaled breath molecular analysis gas chromatograph provided in this application fills the material in the channels on the substrate, which can effectively increase the contact area between the material and the substrate, realize rapid and uniform heating of the material particles, and effectively improve the thermal desorption efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0020] Figure 1 A top view of a thermal desorption sample introduction structure device provided in this application;

[0021] Figure 2 A side sectional view of a thermal desorption sample introduction structure device provided in this application;

[0022] Figure 3 A bottom view of a thermal desorption sample introduction structure device provided in this application.

[0023] Wherein, 10-substrate; 11-channel; 12-channel wall; 13-adsorbent material; 14-filling area; 15-partition; 16-feed inlet; 17-air inlet; 18-air outlet; 19-wide-angle outlet;

[0024] 20-Cover plate; 21-Heating module; 22-First temperature sensor. Detailed Implementation

[0025] This application provides a thermal desorption injection structure device for a breath molecular analysis gas chromatograph, which solves the technical problems of insufficient thermal contact surface of the material in the prior art, inaccurate control of thermal desorption temperature, and low thermal desorption efficiency.

[0026] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0027] like Figure 1 , Figure 2 As shown, this application provides a thermal desorption injection structure device for a breath molecular analysis gas chromatograph, comprising:

[0028] A substrate 10 is provided with a plurality of sequentially connected and recessed filling regions 14. Each filling region 14 is provided with a plurality of channels 11. Adjacent channels 11 form channel walls 12. Material is filled in the channels 11. A partition 15 is provided between the filling regions 14.

[0029] A cover plate 20 is placed on the substrate 10. The distance between the cover plate 20 and the top of the channel wall 12 is less than the diameter of the material. The distance between the cover plate 20 and the top of the partition plate 15 is also less than the diameter of the material.

[0030] The adsorbent material 13 is filled into the channels 11 on the substrate 10. The design of the channels 11 can effectively increase the contact area between the adsorbent material 13 and the substrate 10, realize the rapid and uniform heating of the adsorbent material 13 particles, and effectively improve the thermal desorption efficiency. The cover plate 20 seals the adsorbent material 13 on the substrate 10. The distance between the cover plate 20 and the top of the channel wall 12 is smaller than the diameter of the adsorbent material 13, preventing the adsorbent material 13 from moving between the cover plate 20 and the channel wall 12. Different adsorbent materials can be filled in multiple filling areas 14, and thermal desorption of multiple adsorbent materials can be performed simultaneously.

[0031] The distance between the channel wall 12 and the edge of the filling area 14 is greater than the diameter of the adsorbent material 13, which allows the filling particles (adsorbent material 13) to be transferred between the channels 11 in the filling area 14, and the filling particles can be evenly distributed on the channels 11 of the corresponding filling area 14.

[0032] The height of the channel wall 12 and the distance between the partition plate 15 and the quartz glass are both less than the diameter of the adsorbent material 13, so that the adsorbent material 13 in each region will not mix with each other. The adsorbent material 13 in each filling region 14 can be thermally desorbed more uniformly. The channel wall 12 and the surface of the adsorbent material 13 are wrapped together, which effectively increases the contact area of ​​the adsorbent material 13, improves the heating efficiency, and improves the thermal desorption rate.

[0033] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0034] Specifically, the substrate 10 is a silicon wafer, and the cover plate 20 is quartz glass. A special structure is constructed by etching the silicon wafer. Dry etching of the silicon wafer can effectively control the height of the channel wall 12, and achieve effective regional division of different adsorbent materials 13. The adsorbent materials 13 in different regions will not mix with each other during the filling process. The combination of planar quartz glass and regional heating control can significantly improve the desorption efficiency of the adsorbent materials 13.

[0035] Furthermore, each of the filling regions 14 on the substrate 10 is provided with a feed port 16, which is connected to the side of the filling region 14. Each filling region 14 is provided with a feed port 16 and connected to an air passage. Adsorbent material 13 is filled into the filling region 14 through the feed port 16, so that the adsorbent material 13 in each filling region 14 can be added individually.

[0036] The substrate 10 has an air inlet 17 and an air outlet 18 respectively provided in the filling regions 14 at both ends, and the air inlet 17 and the air outlet 18 are connected to the corresponding filling regions 14.

[0037] During the production process, the air inlet, air outlet 17, feed inlet 18, channel wall 12 and filling area 14 are etched in stages. The etching depths of the air inlet, air outlet, feed inlet, channel wall and filling area are different in order to achieve the functions required by each functional area.

[0038] Optionally, a wide-angle port 19 is provided at the connection between the air inlet 17 and the air outlet 18 and the filling area 14. Specifically, the larger end of the wide-angle port 19 is connected to the filling area 14, so that the airflow in the filling area 14 is more uniform.

[0039] After air enters through the air inlet 17, it passes through each filling area 14 in sequence and is finally output from the air outlet 18. This allows the adsorbent material 13 in each filling area 14 to be guided by the airflow and distributed more evenly in the corresponding filling area 14, resulting in better thermal desorption effect and efficiency. It can simultaneously thermally desorb multiple adsorbent materials 13.

[0040] Furthermore, such as Figure 3 As shown, the thermal desorption sample introduction structure device also includes a controller. A heating module 21 and a first temperature sensor 22 are provided on the back side of each filling area 14 on the substrate 10. The heating module 21 and the first temperature sensor 22 are both connected to the controller. An insulating layer is deposited between the heating module and the temperature sensor and the silicon substrate. The insulating layer is SiO2 or SiNx. In this embodiment, the heating module 21 is a heating resistance wire or a heating rod.

[0041] Specifically, the thin films on the surfaces of the heating module 21 and the first temperature sensor 22 are fabricated using magnetron sputtering or vapor deposition equipment. The materials used for the thin films on the surface of the heating module 21 include, but are not limited to, one of Au, Pt, Al, Cu, etc.; the materials used for the thin films on the surface of the first temperature sensor 22 include, but are not limited to, one of Pt, Ni, etc.

[0042] Each region at the bottom of the silicon wafer is filled with an independent heating module 21 and an independent first temperature sensor 22, which can independently and quickly heat the desorption material in different filling regions 14. When the appropriate temperature is reached, the controller controls the heating module 21 to stop heating, so that the temperature of the filling region 14 can be precisely heated and controlled. Furthermore, specific thermal desorption temperature settings can be made for two VOCs with similar separation degrees to achieve better desorption effect.

[0043] The controller can be a microcontroller, which allows for rapid adjustment of the heating time and power for each filling region through microcontroller program and hardware control. It also enables independent control of the temperature rise curve for each region, effectively improving injection efficiency and optimizing injection results, thereby obtaining narrower peak widths in the chromatogram.

[0044] By controlling the thermal desorption temperatures of different VOCs, different thermal desorption temperatures can be set for two VOCs with similar separation degrees, allowing them to enter different adsorption material regions 13. Then, specific temperature programs are applied to the corresponding regions to achieve effective regional-time separation of VOCs with similar separation degrees, thus achieving better separation results.

[0045] The working principle of the sample introduction device in this scheme is as follows: First, the inlet 17 needs to be sealed. Then, the adsorbent material 13 is placed into the feed inlet 16. A negative pressure pump is connected through the outlet 18 to create a negative pressure in the filling area 14. The negative pressure draws the adsorbent material 13 into the filling area 14. After the filling area 14 is filled with the adsorbent material 13, the feed inlet 16 is sealed, and the inlet 17 is opened. The gas is connected to the pump through the inlet 17, and the gas flows into the filling area 14 from the inlet 17 and finally exits from the outlet 18. As the adsorbent material 13 flows out, it is affected by the airflow in the filling area 14 and is arranged in the channel 11. It is evenly distributed between adjacent channels 11, so that the contact surface between the adsorbent material 13 and the silicon wafer is larger. During the thermal desorption process, the silicon wafer is heated by passing electricity through the heating resistance wire. The channel wall 12 and the bottom surface of the channel 11 of the silicon wafer will heat the adsorbent material 13. The first temperature sensor 22 detects the temperature of the corresponding filling area 14, so that the temperature of the filling area 14 is kept constant, and the thermal desorption effect is better.

[0046] Preferably, a heat insulation layer is provided on both sides of the partition. In this embodiment, the heat insulation layer is made of aerogel felt or vacuum board. The heat insulation layer serves to prevent heat conduction to adjacent areas.

[0047] Specific working principle:

[0048] First, the air inlet 17 is blocked, the material 13 is adsorbed in the feed inlet 16, and the air outlet 18 is pumped out by the air pump to fill the channel 11 with the material. After filling, the feed inlet 16 is blocked and the air inlet 17 is opened.

[0049] Secondly, the air inlet 17 is vented to allow the material to be evenly distributed in the filling area 14;

[0050] Finally, the heating module 21 is turned on and the temperature is set to heat the material, and the adsorbed material 13 undergoes thermal desorption.

[0051] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0052] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A thermal desorption sample introduction structure device for a gas chromatograph for breath molecular analysis, characterized in that, include: A substrate having a plurality of sequentially connected and recessed filling regions, each filling region having a plurality of channels, adjacent channels forming channel walls, material being filled in the channels, and partitions being provided between the filling regions. A cover plate, which covers the substrate, wherein the distance between the cover plate and the top of the channel wall is less than the diameter of the material, and the distance between the cover plate and the top of the partition is less than the diameter of the material; The substrate has an air inlet and an air outlet respectively provided in the filling areas at both ends, and the air inlet and air outlet are connected to the corresponding filling areas. Different adsorbent materials are filled in several filling areas; The thermal desorption sample introduction structure device also includes a controller. A heating module and a first temperature sensor are provided on the back side of the substrate for each of the filling areas. The heating module and the first temperature sensor are both connected to the controller. An insulating layer is deposited between the heating module and the temperature sensor and the silicon substrate. The insulating layer is SiO2 or SiNx. The partition is provided with heat insulation layers on both sides.

2. The thermal desorption injection structure device for a gas chromatograph used for exhaled molecular analysis as described in claim 1, characterized in that, The distance between the channel wall and the edge of the filling area is greater than the diameter of the material.

3. The thermal desorption injection structure device for a gas chromatograph used for exhaled breath molecular analysis as described in claim 1, characterized in that, Each of the filling areas is provided with a feed port on the substrate, and the feed port is connected to the side of the filling area.

4. The thermal desorption injection structure device for a gas chromatograph used for exhaled breath molecular analysis as described in claim 3, characterized in that, The air inlet, air outlet, feed inlet, channel wall, and filling area are etched in stages, with different etching depths for the air inlet, air outlet, feed inlet, channel wall, and filling area.

5. The thermal desorption injection structure device for a gas chromatograph for exhaled breath molecular analysis as described in claim 1, characterized in that, The air inlet and outlet are provided with wide-angle openings at the connection points with the filling area.

6. The thermal desorption injection structure device for a gas chromatograph for exhaled breath molecular analysis as described in claim 1, characterized in that, The thin films on the surfaces of the heating module and the first temperature sensor are fabricated using magnetron sputtering or vapor deposition equipment. The thin film on the surface of the heating module is made of one of Au, Pt, Al, or Cu; the thin film on the surface of the first temperature sensor is made of one of Pt or Ni.

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